CIE A Level Chemistry
CIE A Level Chemistry An Introduction to AS Level Organic Chemistry Exam Questions
Free CIE A Level Chemistry exam questions for An Introduction to AS Level Organic Chemistry, with a mark scheme for every pack. Covers formulae, functional groups, nomenclature, homologous series, bond fission, reaction types, mechanisms, and structural and stereoisomerism including optical isomers.
An Introduction to AS Level Organic Chemistry exam questions
1 question pack of real past exam questions, each with its mark scheme. Do not stop after a few: answer as many as you can without notes, then mark every answer with the mark scheme. The more questions you do, the more quickly you will spot how examiners ask about each idea.
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A-Level Chemistry Flashcards for 2027 Onwards
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Then test yourself with the questions on this page.
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About CIE A Level Chemistry An Introduction to AS Level Organic Chemistry
An introduction to AS Level organic chemistry sets out the language you will use for every organic topic in Cambridge International 9701. You learn to write general, structural, displayed and skeletal formulae, recognise functional groups and name compounds systematically. The topic introduces homologous series, homolytic and heterolytic fission, free radicals, electrophiles and nucleophiles, and classifies reactions as addition, substitution, elimination, hydrolysis, condensation, oxidation and reduction. Isomerism is a major part: structural (chain, positional and functional group) and stereoisomerism (geometrical and optical). The A Level extension adds naming of aromatic compounds and more complex stereochemistry. Examiners frequently test identifying chiral centres, drawing isomers and using curly arrows correctly.
What you need to know
- Formulae Be able to convert between molecular, general, structural, displayed and skeletal formulae. Skeletal formulae show carbon chains as lines with functional groups drawn in.
- Nomenclature Name compounds with up to six carbons in the main chain using the longest chain, lowest locants and alphabetical order of substituents, for example 2-methylpropan-1-ol.
- Bond fission and reactive species Homolytic fission gives two free radicals, each with an unpaired electron. Heterolytic fission gives ions. An electrophile accepts a pair of electrons and a nucleophile donates one.
- Reaction types and curly arrows Learn addition, substitution, elimination, hydrolysis, condensation, oxidation and reduction. A curly arrow shows the movement of a pair of electrons from a bond or lone pair.
- Structural isomerism Same molecular formula but different structural formula: chain, positional and functional group isomers. Aldehydes and ketones, and acids and esters, are common functional group isomer pairs.
- Geometrical isomerism Cis-trans isomers occur because there is restricted rotation about a C=C double bond and each carbon of the double bond has two different groups attached.
- Optical isomerism A chiral centre is a carbon atom attached to four different groups. The two enantiomers are non-superimposable mirror images, and should be drawn in 3D with wedge and dash bonds.
Common mistakes in An Introduction to AS Level Organic Chemistry
- Starting a curly arrow from an atom with no lone pair or ending it at nothing; it must start at a bond or lone pair and end at an atom or bond.
- Saying cis-trans isomerism is due to no rotation at all; it is restricted rotation about the C=C bond.
- Marking a carbon as chiral when two of its groups are the same, such as CH3 and CH3.
- Drawing optical isomers that are not true mirror images or are identical when rotated.
- Choosing a shorter chain for naming because the branch is drawn horizontally; always find the longest continuous chain.
Try three An Introduction to AS Level Organic Chemistry exam-style questions
1. Butan-2-ol shows optical isomerism. Explain why and draw the two isomers. (3 marks)
Show the mark scheme answer
Carbon 2 is a chiral centre with four different groups (H, OH, CH3, C2H5); two 3D tetrahedral structures drawn; as mirror images of each other.
2. Draw and name two structural isomers with the formula C4H10. (2 marks)
Show the mark scheme answer
Butane, CH3CH2CH2CH3; 2-methylpropane, CH3CH(CH3)CH3.
3. Define the terms nucleophile and homolytic fission. (2 marks)
Show the mark scheme answer
Nucleophile: a species that donates a pair of electrons (to form a covalent bond); homolytic fission: a covalent bond breaks with one electron going to each atom, forming two free radicals.
An Introduction to AS Level Organic Chemistry FAQs
What does Cambridge AS Level Chemistry An introduction to organic chemistry cover?
It covers formulae, functional groups, naming, bond fission, reactive species, reaction types, and structural and stereoisomerism.
How do I revise organic nomenclature?
Practise naming and drawing a wide range of compounds, especially with branches and two functional groups, and check your locants are as low as possible.
What definitions do I need for the organic introduction?
Homologous series, functional group, structural isomer, stereoisomer, chiral centre, free radical, electrophile, nucleophile, homolytic and heterolytic fission.
